The present invention relates in general to sign constructions, and in particular to a new and useful single or multiple face sign which utilizes flexible sign face material.
A wide variety of tensioning system for flexible sign face is known. See for example U.S. Pat. No. 3,885,335 to Egermayer which shows a double face sign having flexible face material and edge systems for tensioning the material. A back lighted sign using flexible material is also disclosed in U.S. Pat. No. 4,185,408 to Tracy. A sign having a flexible sheet material stretched on a heavy duty frame which is hinged to a sign box is disclosed in U.S. Pat. No. 4,516,343 to Stilling.
Flexible double face signs on the order of eight feet square and smaller are not economically feasible when compared to double face rigid acrylic signs common in the industry today.
Flexible double face signs with lighted graphics or displays on opposite sides require a stronger frame than rigid acrylic double face signs. Tensioning of the flexible vinyl creates a stress load of 30 lbs per square foot (pfs) that must be resisted by the frame. The flexible vinyl also transmits wind loads to the frame in a different manner than rigid acrylic, again requiring additional frame strength. Adding strength to the frame creates an exponential increase in cost and weight. The cost vs. strength equation has created an economic barrier in the sign industry which no one has been able to overcome.
In addition, one or both sign faces in a double face sign must be hinged to open and provide access to the interior of the sign for lamp and ballast maintenance. A rigid frame around the perimeter of the flexible sign face must be strong enough to resist tensioning and wind loads.
SUMMARY OF THE INVENTION
The present invention provides a sign with a low strength, light weight cover frame in combination with a stronger main sign frame which is comparably priced and stronger than rigid acrylic signs.
The frame of the invention is required only to hold the flexible sign face. Tension is completed only when the hinged or removable cover frame of the sign is closed and secured to the main sign frame. The main sign frame is inherently strong enough to resist all loads involved.
By combining a low strength, light weight cover frame with a rigid and strong main side frame, and an appropriate apparatus to tension the flexible sign face when the two frames are fixed to each other, the invention provides a relatively large flexible sign face with no seams. In addition, the sign face may be selected to match the color scheme, designs and texture of other flexible face signs used at a particular installation, for example, a gas station or convenience store. Accordingly, an object of the present invention is to provide a sign comprising, a rigid main frame having at least one face plane, a tension edge member connected to the rigid frame and having a tensioning edge extending parallel to the plane, a removable cover frame detachably connected to said main frame at said plane, at a location outwardly spaced from said tensioning edge, a flexible sign face for carrying a sign display and having a plurality of outer edges, preliminary tensioning means connected between the sign face edges and the cover frame for pretensioning the sign face on the cover frame, and final tensioning means connected between the cover frame and the main frame for urging the cover frame toward the plane of the main frame to press the flexible sign face against the tensioning edge to complete tensioning of the flexible sign face.
Another object of the present invention is to provide a sign which utilizes flexible face material and which is simple in design, rugged in construction and economical to manufacture.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which the preferred embodiments of the invention are illustrated.